450 Allgemeines. 



Wirkung auf Organismen" (Desiniection durch Ionen, Parthe- 

 nogenese durch Ionen u. s. f.) und über Permeabilität der 

 Plasmahaut (O verton 's neue Untersuchungen, intravitale Zell- 

 färbung u. A.). Das vorletzte Capitel handelt über die Fer- 

 mente, das letzte vom dynamischen Gleichgewicht im Organismus, 

 über Einfluss von Temperatur und Druck und über das Wachs- 

 thum. Auch diejenigen Capitel, welche in erster Linie für den 

 Mediciner geschrieben sind (Resorption; Blut, Milch und 

 Harn; Secretion und Lympfbildung), bringen dem Botaniker 

 vielfache Anregung. 



Auf Einzelheiten einzugehen, erscheint bei dem reichen In- 

 halt des Buches nicht angängig. Den Fachgenossen sei das 

 Werk zur Leetüre warm empfohlen. Küster. 



WARD, H. MARSHAL, On the histology of Uredo dispersa 

 Eriks s. and the „Mycoplasm" Hypothesis. (Royal 

 Society Proceedings. April 1903. Vol. LXXI. No. 473. 

 p. 353.) 



The following Abstract of the füll paper is given in this 

 number of the Royal Society Proceedings: 



„The paper deals with a detailed study of the histological 

 features of the germination, infection, and growth of the 

 mycelium of the Uredo in the iissues of grasses. Primarily, 

 the figures refer especially to the Uredo of Puccinia dispersa 

 in the tissues of Bromus secalinus but comparisons are made 

 with the behaviour of this and other Uredineae — e. g. Pucci- 

 nia glumarum and P. graminis — in the tissues of other grasses 

 and cereals. 



The research, which has been carried on over a year and 

 a half and has involved the preparation and microscopic exami- 

 nation of thousands of sections, is principally based on the 

 application of improved hardening and staining methotls to 

 preparations from tube eultures of the grasses concerned, the 

 leaves of which were infected at definite spots. The tube 

 eultures were prepared aecording to the method previously 

 deseribed. (Roy. Soc. Proc. 1902. Vol. LXIX. p. 461.) At definite 

 intervals after sowing the spores ■ e. g. after 1,2, to 6 and 

 8 days the infected areas were removed and placed in 



fixing Solutions, and the life history of the fungus traced step 

 by step, and controlletl by reference to uninfected areas. 



The füll paper is illustrated by numerous figures, and deals 

 with the behaviour of the nuclei, vacuoles, septa, branches, 

 haustoria, and other details of the hyphae up to the commen- 

 cement of spore-formation. 



The relations of the hyphae and haustoria to the cell Con- 

 tents of the host are eritieally examined, and the cumulative 

 evidence not only fails to support Eriksson 's Mycoplasm 

 hvpothesis; but is completely subversive of it, so far as histo- 

 lo ical facts are concerned. 



